A cooling device includes an electrode unit which is arranged in a space between adjacent radiation fins and which is electrically insulated from the radiation fins, and a power supply source which applies a voltage between a heat radiation structure and the electrode unit. The cooling device is further provided with an insulation resistance detection unit which calculates an insulation resistance between the heat radiation structure and the electrode unit, and a comparison unit which compares the insulation resistance calculated by the insulation resistance detection unit with a predetermined threshold, wherein, as a result of the comparison of the calculated insulation resistance and the predetermined threshold by the comparison unit, when the calculated insulation resistance is lower than the predetermined threshold, the cooling device is adapted to judge that the radiation fins have clogged.